Datasheet

The need to create an Integer object to place an int into the collection is no longer needed. The boxing

conversion happens such that the resulting reference type’s

value() method (such as intValue() for

Integer) equals the original primitive type’s value. Consult the following table for all valid boxing con-

versions. If there is any other type, the boxing conversion becomes an identity conversion (converting

the type to its own type). Note that due to the introduction of boxing conversions, several forbidden con-

versions referring to primitive types are no longer forbidden because they now can be converted to cer-

tain reference types.

Primitive Type Reference Type

boolean Boolean

byte Byte

char Character

short Short

int Integer

long Long

float Float

double Double

Unboxing Conversions

Java also introduces unboxing conversions, which convert a reference type (such as Integer or Float)

to its primitive type (such as

int or float). Consult the following table for a list of all valid unboxing

conversions. The conversion happens such that the

value method of the reference type equals the

resulting primitive value.

Reference Type Primitive Type

Boolean boolean

Byte byte

Character char

Short short

Integer int

Long long

Float float

Double double

Part I: Thinking Like a Java Developer

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